Riveting means and method



Nov. 23, 1965 D. G. DOWNES 3,218,701

RIVETING MEANS AND METHOD Filed Oct. 10, 1962.

44 INVENTOR.

DOUGLAS DOWNES MQWW ATTORN EYS United States Patent 3,218,701 RIVETINGMEANS AND METHOD Douglas G. Downes, Natick, Mass, assignor to Judson L.Thomson Manufacturing Company, Waltham, Mass., a corporation ofMassachusetts Filed Get. 10, 1962, Ser. No. 229,650 12 Claims. (Cl.29-464) The present invention relates to clinching rivets and moreparticularly to an improved jig and methods of forming and employing thejig. The jig of this invention is particularly useful for positioning amultiplicity of elements to be clinched together in a rivet clinchingmachine as well as for clinching rivets on a single element.

It is often desirable to rivet together a plurality of preformedelements having preformed rivet holes. Normally the preformed parts arehand assembled and clinched in conventional riveting machines. Theoperator normally places a rivet in a conventional hand riveting machinewith the head down and the shank of the rivet extending upwardly. Theoperator then slides the rivet hole in each piece to be riveted, overthe shank of the rivet and activates a hand riveting machine, such as anarbor press, to bring a hammer into engagement with and peen over thefree uppermost end of the rivet while the rivet head is supported by ananvil. As the operator places each workpiece on the rivet care must betaken to align each hole with the rivet shank. This method is extremelytime consuming and limits production rates since the machine can work nofaster than the hand assembly process which is greatly slowed down bythe alignment step. It is particularly time consuming where theworkpieces being riveted together must rotate with respect to oneanother, as no self aligning projection can be formed on the workpiecesin such cases.

In another method, costly dies of various types are used to position theworkpieces to be clinched together in preselected positions in theriveting machine. These dies must be specially formed for eachconfiguration of each workpiece to be clinched together. In many cases,the configurations of the parts are irregular or highly complex addingfurther to the cost of forming dies. Due to the high cost involved inthis method, the previously described hand assembly method is employedfor riveting such workpieces except in those cases where large numbersof similar parts or sets of parts are to be clinched together.

It is an important object of this invention to provide a jig for use ona rivet clinching machine for accurately and efiiciently positioning amultiplicity of elements to be clinched together in a method which maybe easily automated.

It is another important object of this invention to provide a jig foruse on a rivet clinching machine for accurately and efiicientlypositioning a single element allowing a rivet to be clinched to theelement.

It is another important object of this invention to provide a method offorming jigs in accordance with the preceding objects which areextremely inexpensive, utilize scrap materials and can be carried out ina minimum of time using a minimum of mechanical skill.

It is still another object of this invention to provide a method ofclinching together and positioning a multiplicity of elements in aconventional riveting machine using an inexpensive jig in accordancewith preceding objects, which method is easily automated and allows massproduction at high manufacturing rates.

It is a still further object of this invention to provide a method ofclinching a rivet through a hole in a single element using aninexpensive jig formed in accordance with the preceding objects.

'ice

According to the invention, a jig is preferably formed by die cuttingfrom a member one of the elements of a multiplicity of elements to beclinched together. This results in the member being formed with a blankhaving a cutout conforming with the outline of the element. The elementis then replaced in the cutout. A hole for a rivet shank is preferablydie cut into the element at the same time that it is cut out of theblank. The blank is provided with holes so that it may be pinned orotherwise secured after further processing to the rivet machine tosupport the workpieces being processed between the hammer and anvil. Thecutout is then further shaped and cut so that other elements to bejoined to the first element may be projected through the cutout.

In use, the jig is relocated in the preselected position on the rivetingmachine and the second element or a plurality of elements is insertedthrough the cutout portion and about an upstanding conventional pilot ofa riveting machine. The first element is then reinserted into the cutoutportion with the bore of the first and second element coaxially aligned.A rivet is positioned with its head or head uppermost and coaxiallyaligned with the bores. A hammer is then actuated to clinch the rivetwith the elements between the hammer and the anvil. This methodminimizes the time required for clinching the rivet and assembling theparts as well as drastically reduces the cost of the jig since themember may be a scrap piece from which the first element has been out.In addition, the method is well suited to automation since positivepositioning of the elements is easily accomplished. Positive positioningis extremely important when clinching shoulder rivets to plural elementswhich rotate about said rivet.

In an alternate embodiment of the invention a rivet may be clinched to asingle element employing a jig made from a scrap member.

These and other objects and advantages of the present invention will bemore clearly understood when considered in connection with theaccompanying drawings is which:

FIG. 1 is a cross-sectional view showing a completed clinched rivetassembly of this invention;

FIG. 2 is an exploded view of two elements and a rivet therefor;

FIG. 3 is a top plan view of a scrap member of this invention having acutout;

FIGS. 4 and 5 are top plan views of the member of FIG. 3 showing furtherprocessing thereof;

FIG. 6 is a cross-sectional view through an assembly tcl)1 be rivetedshowing portions of a known riveting mac me;

FIG. 7 is a side View partially in cross section of a single rivetedelement; and

FIG. 8 is a cross-sectional view through a rivet assembly showingportions of a known riveting machine.

FIG. 9 is a fragmentary perspective view of a dowel pin useful in thisinvention.

With reference now to the drawings and particularly FIGS. 1 and 2, arivet assembly 10 i shown assembled and clinched in accordance with themethod of this invention. The rivet assembly 10 preferably comprises arivet 4 having a flat head 5, a shoulder 6, shank 7 and a clinched end8. The particular type of rivet employed may vary considerably, forexample, beaded rivets, straight shank rivets and flat ended solidrivets may be used if desired. However, the invention is particularlyuseful for securing rivets having shoulders as illustrated.

A first element 2 is joined to a second element 3 in facing adjacentplanar alignment. In the illustrated embodiment, the clinched end 8actually bites into the second element 3 preventing rotation of therivet in relation to the second element 3 but allowing rotation of thefirst element 2 with respect to the rivet and second element 3. Inalternate embodiments of the invention, the clinching force may beincreased or straight shank rivets may be employed so as to preventrotational movement of the elements if desired.

The first element 2 preferably has a planar configuration having acurved outline with a rivet shoulder receiving bore 9 extendingperpendicular to the plane of the element. The element 2 may have anyouter configuration according to its particular desired usage and may,as in the illustrated embodiment of the invention, comprise a linkage orconductive member arm which has a wave outline. The linkage arm 2 is cutpreferably by die cutting or stamping it from a fiat or planar member20, thereby simultaneously forming the member 20 with a blank having acutout 21 which conforms closely with the outline of the element. Anyprocedure which utilizes a die to cut the element from sheet stock maybe employed in this invention and considered to be included in the termdie cutting. The second element 3 may have varying outer configurationsbut is preferably formed in the same manner as the first element and inthe illustrated embodiment is a planar linkage bracket 3 which has abore 11 of slightly smaller diameter than the bore 9 and is adapted toreceive the shank portion of the rivet 4. Both the first element 2 andthe second element 3 may vary considerably in thickness size, outlineand number of rivet bores provided. The bracket 3' may have an outeroutline covering a larger area than the end portion of the linkage arm 2which carries the bore 9.

The particular materials employed for the member 20, first element 2 andsecond element 3 may vary. Any materials capable of being stamped or cutfrom sheet stock may be used. For example, the elements may be composedof plastics, such as nylon, polyethylene, styrene or metals such assteel, tin, copper, etc.

In prior art procedures the member 20 from which the first element 2 iscut is normally discarded or considered to be scrap. However, in thisinvention the member 20, which is normally scrap, is useful in formingthe inexpensive and highly accurate jig of the present invention.

The jig is formed by firstrepositioning the first element 2 within thecorresponding cutout 21 of a scrap member 20. In some cases the element2 may be only partially cut from the member 20 and allowed to remain inthe cutout portion until later processing of the jig. Any first elementcut by the same die used in forming the cutout 21 may be repositioned inthe scrap member 20. As used in connection with positioning in thecutout 21 the term first element may in this application be any firstelement cut by the same or an identical die as the cutout. As shown inFIG. 4 the bore 9 of the first element 2, While located in the cutout21is then positioned directly above a pilot of a conventional rivetingmachine and their respective axes are coaligned. This may be donepreferably, by replacing the pilot of the machine with a dowel pin suchas partially shown in FIG. 9, having an outer diameter only slightlysmaller than the diameter of bore 9. The member 20 is then pusheddownwardly against the pressure of bellows 32 until the top of the dowelpin projects through or into bore 9 and thereby coaligns the respectiveaxes of the bore 9 and dowel pin. Because these elements havesubstantially the same diameters there is a greater degree of accuracythan would be the case if the pilot were used since the pilot ofnecessity must have a much smaller diameter than the bore so as toaccommodate the thickness of the rivet shank. Locating holes 23 whichpreferably are provided in the scrap member 20 previous to the priorpositioning or at anytime after the scrap member is located in theriveting machine are then located on the riveting machine by suitablemeans or marking for subsequent securing. These holes 23 are used toreceive screws or other attachment means for firmly and preciselylocking and positioning the scrap member 20 in a conventional rivetingmachine so that the axis of the pilot is coaxial with the bore 9 when anelement 2 is located within the jig.

After correlating the holes 23 of the member 20 with marks on theriveting machine so that the member 20 may be secured to the machinewith the pilot of the machine aligned with the axis of bore 9, themember 20 may be removed for the subsequent formations of an additionalcutout.

The cutout 25 may be formed by die stamping or other cutting or grindingmeans after points 22 have been located and marked. Points 22 are markedwhile the element 2 is in cutout 21 using the center of bore 9 as areference point. These points 22 are preferably marked when the member20 carrying element 2 is located in a riveting machine as described inthe previous paragraph. Points 22 define the perimeter of cutout 25 andmay be shaped to be slightly larger than element 3 but conforminggenerally in outline thereto but preferably locate a circle having adiameter larger than any width of element 3. As indicated the scrapmember 20 preferably is removed from the riveting machine and the cutout25 made whereupon the scrap member is located and secured to theriveting machine by means of screws passing through holes 23 into themachine.

The jig 29 is shown in its completed form in FIG. 5. A substantialportion of the cutout 21 adjoins the enlarged cutout 25 allowing a firstelement 2 to be positively positioned by the remaining portion of cutout21 with the axis of the bore 9 aligned with the axis of pilot 34.

The improved and inexpensive jig of this invention may be used inconventional riveting machines such as riveting machines of the typepartially shown in FIG. 6. A support plate 33 is horizontally located bya resilient spring bellows 32. A reciprocally moveable pilot 34 having anarrow diameter portion 39 with a blunted end 40 extends upwardlytowards a centrally located hole in the support plate 33. An anvil 50surrounds the pilot portion 39 and is fixedly mounted within the supportplate 33 and is adapted to pe-en the lower end of a rivet as will bedescribed. A reciprocably moveable hammer or plunger and stem 30 isaxially aligned with and mounted for reciprocation towards the pilot 34.Support plate 33 has a centrally located recess 31 which forms alocating means for positioning the second element or bracket 3 with itsbore 11 coaxially aligned with pilot 34. In some embodiments of theinvention the recess 31 is larger than the outline of the second elementand simply permits the second element 3 to be recessed so that its topsurface is in facing planar relation with a plane drawn through thelower surface of the jig 29 when the jig 29 is positioned in theriveting machine. In these embodiments the position of bore 11 is fixedby placing the element 3 in the riveting machine with the pilot enteringbore 11.

The completed jig 29 is preferably firmly attached to the support plate33 by conventional attaching means such as screws passing throughlocating holes 23. Alternatively fixed locating pins may be provided inthe riveting machine adapted to extend vertically from the support plateand enter holes 23.

In use, the second element or bracket 3 is projected through theenlarged cutout 25 of the jig 29 and into its predetermined position inthe recess 31 with the bore 11 surrounding the pilot portion 39. Thecutout 25 is large enough to allow passage of bracket 3 therethroughwhen the bracket and jig are in planar alignment. Subsequently, thefirst element 2 is reinserted into the cutout portion 21 with an endthereof projecting into the enlarged cutout 25 and with bore 9 coaxiallyaligned with bore 11 and pilot 34. In this position the elements 2 and 3are in adjacent facing planar relationship and the pilot end 40 projectsabout /8 inch above element 2. A conventional rivet feed may be employedto automatically feed a rivet 4 into the position shown in FIG. 6 andthe rivet 4 is aligned by the pilot end 40. Subsequently the rivet maybe positioned within the bores 9 and 11 by bringing the hammer 30 downto clinch the end 8 between the anvil 50 and hammer 30 as the pilot 34is reciprocated to a lowermost position (not shown).

It is a feature of this invention that shoulder rivets such as 4 can bepositively aligned with a first bore 9 and a second bore 11 using thenovel jig 29. In many cases the bore 9 has a radius of as little as0.0005 inch larger than the diameter of shoulder portion 6. Positive,rapid alignment as by the present invention may be easily andefiiciently accomplished.

In an alternate embodiment of the invention, a single element such as 2having a preformed bore 9 may have a solid rivet 41 clinched thereon asshown in FIG. 7. In this case the member as shown in FIG. 4 having thesingle cutout 21 is the completed jig. The jig 20 is located in ariveting machine of the type illustrated generally in FIG. 8 having aresilient bellows 42 supporting a ring shaped horizontal mounting plate43. A conventional anvil 44 is fixedly located below a central cutout ofplate 43 and a reciprocally moveable hammer 45. In some cases the anvil44 may be reciprocally moveable along a vertical path having anuppermost limit on a plane through the top surface of plate 43.

In the alternate embodiment, the jig 20 with the element 2 positioned incutout 21 is placed on the surface of plate 43. A locating or dowel pin(not shown) having a diameter slightly smaller than bore 9 and snuglyfitting in the bore is then positioned through bore 9 and replaces theanvil 44 in the machine. This step locates bore 9 in its desiredposition with respect to anvil 44, the axis of the pin and the mechanismwhich secures it. When the proper alignment is achieved jig 20 isscrewed or otherwise fastened to plate 43 through holes 23 and the pinis removed and anvil 44 is replaced. The anvil thereby is coaxial withbore 9. Successive elements 2 can then be positioned in cut-out 21 andriveted by inserting a rivet 41 with its solid shank down into bore 9.The hammer 45 then strikes the rivet head and clinches the free shankend against anvil 44.

It is a feature of this invention that the use of the scrap jig 29allows positive positioning of elements to be clinched in rivetingmachines. The cutout portion 21 in the jig is exactly matched to theoutline of a portion of element 2 since they are made from the same oran identical die. The clinching procedure may be easily automated byproviding conventional feeding apparatus to place the elements in theirpredetermined positions and remove the assembly from the rivetingmachine.

A further feature of this machine is that the rivet 4 is placed withinthe bores 9 and 11 with its head 5 in an uppermost position and theshank 7 extending downwardly. This feature allows the workpieces orelements to be clinched to be positively positioned previous to thepositioning of the rivet and facilitates ease of assembly of the parts.

One more feature of the machine is that the jig may be formed of aninexpensive scrap member having a cutout portion formed by an actual diecutout of one of the elements. Any errors in die construction therebywould appear both in the jig and the members thus insuring positivepositioning and close fitting of the element 2 in the jig. The jig canbe used to successively position identical pairs of elements cut fromthe same die in the riveting machine.

While there has been shown and described specific embodiments of thepresent invention, it should be under stood that those skilled in theart may now make many modifications and variations thereof. For example,a plurality of jigs 29 may be employed when more than two elements areto be riveted together. When a third element is used between elements 2and 3, a second jig 29 having suitable cutout portions as abovedescribed partially conforming to the outline of the third element willbe located between the support plate 33 and the first jig 29. In thiscase it is only necessary that all the cutouts 21 and 25 of the firstjig 29, be at least as large as the cutout portion 21 and 25 of thesecond jig.

In another modification of the invention, when the second element orbracket 3 is die stamped, the cutout scrap member of the die stampingmay be employed and firmly afiixed to the support plate 33 to locatebracket 3 in the riveting machine. In this modification the recess 31may be eliminated and support plate 33 is substantially planar.

The breadth of this invention is to be construed as limited only by thespirit and scope of the appended claims.

What is claimed is:

1. A method of forming a jig for use on a rivet clinching machine,

said jig being useful for positioning a multiplicity of elements to beclinched together by a rivet, said method comprising die cutting a firstone of said elements from a member whereby said member is formed as ablank having a cutout shaped to conform with the outline of said oneelement,

replacing said one element in said cutout,

locating the position of said member by said one element located in saidcutout through which said rivet is to extend, and

further shaping said cutout whereby said other elements may be projectedthrough said cutout. 2. A method of forming a jig for use in a rivetclinching machine,

said jig being useful for positioning a multiplicity of elements to beclinched together by a headed rivet,

cutting a first one of said elements from a member whereby said memberis formed into a blank having a cutout shaped to conform with theoutline of said one element,

positioning said one element is said cutout,

while said one element is in said cutout locating the position in saidone element through which said rivet is to extend to position saidmember, and further shaping a portion of said cutout whereby at leastone other element may be projected through said further shaped cutoutportion after said first element is removed from said member and saidfirst element may be replaced in said member in abutting relation withsaid other element.

3. A method of forming a jig for use on a rivet clinching machine havinga coaxially aligned hammer and pilot, said jig being useful forpositioning a plurality of elements to be clinched together by a rivet,said means comprising,

cutting a first one of said elements from a member whereby said memberis formed into a blank having a cutout shaped to conform with theoutline of said one element,

said one element having a bore therein adapted to receive a rivet,

locating said one element in said cutout,

locating said member with said element contained therein in apreselected position between said hammer and said pilot with said borecoaxially aligned with said pilot,

further shaping a portion of said cutout in the vicinity of said bore toallow at least one other of said plurality of elements to pass throughsaid cutout when said other element is in planar alignment with saidblank.

4. A method in accordance with claim 3 and further comprising the stepof afiixing said member in said preselected position to said rivetclinching machine whereby successive elements corresponding in outlineto said one element may be successively positioned in said cutout.

5. A method in accordance with claim 3 wherein said member and saidelement are substantially coplanar.

6. A method in accordance with the method of claim 3 wherein said pilotis replaced by a dowel pin having a diameter adapted to allow said boreto snugly and slideably surround said dowel pin, and

said member with said one element contained therein is located in apreselected position dictated by said bore surrounding said dowel pin.7. A method of assembling a plurality of elements to be clinchedtogether with a rivet clinching machine, said machine having ahorizontally extending support plate with locating means on said supportplate for locating a first of said elements adjacent thereto, a pilotextending below and perpendicular to said plate adjacent to meansdefining an opening in said plate and a jig formed by (1) cutting asecond of said elements from a member whereby said member is formed intoa blank having a cutout shaped to conform with the outline of saidsecond element, said second element having a bore therein adapted toreceive a rivet, (2) locating said second element in said cutout, (3)locating said member with said second element contained therein in apreselected position coaxially aligned with said pilot, (4) furthershaping a portion of said cutout in the vicinity of said bore to allowsaid first element to pass through said cutout when said first elementis in planar alignment with said member,

said assembling method comprising positioning said first elementadjacent said support plate and located in said locating means,relocating said second element in said cutout overlying and in facingrelation with said first element with preformed rivet receiving bores ofsaid first and second elements being axially aligned with each other andwith said pilot,

positioning a rivet above said second element with the shank of saidrivet extending downwardly from a head of said rivet,

forcing said shank into said first and second element bore and clinchingsaid rivet.

8. A jig useful for assembling and locating a plurality of elements in arivet clinching machine adapted to clinch said elements together with arivet, said jig comprising,

a member having a means defining a cutout,

said means defining a cutout having a first portion cut by a die whichis the same die used to cut a first element of said plurality ofelements and a second portion coextensive with said first portion andlarger than a portion of said first element and the outline of a secondelement of said plurality of elements, whereby said first portion ofsaid means defining a cutout corresponds to a first portion of saidfirst element and said second portion of said means defining a cutoutallows passage of said second element therethrough.

9. A jig in accordance with claim 8 wherein said member is substantiallyplanar and positioning means are provided therein for positioning saidmember in a riveting machine.

10. A method of forming a jig for a riveting maching, said rivetingmachine comprising a support plate, an anvil and a hammer axiallyaligned with said anvil, said method comprising,

cutting a first element having a rivet hole therein from a surroundingmember whereby a cutout corresponding in outline to said element isformed in said member,

locating said element in said cutout and axially aligning said rivethole with said anvil and hammer, and afiixing said member to saidsupport plate.

11. A method in accordance with claim 10 wherein said element is rivetedin said machine and subsequently removed from said machine wherebysuccessive elements corresponding in outline to said element may bepositioned in said cutout and riveted.

12. A reusable jig for use in a riveting machine, comprising a member,

said member having a cutout therein conforming in outline to an outlineof a first element to be positioned in said jig,

said cutout being formed by a die used to out said element,

and means on said member for attaching said member to said rivetingmachine whereby successive elements substantially identical to saidfirst element can be successively positioned in preselected positions insaid riveting machine.

References Cited by the Examiner UNITED STATES PATENTS 2,829,488 4/1958Valli 59-79.5

WILLIAM J. STEPHENSON, Primary Examiner.

1. A METHOD OF FORMING A JIG FOR USE ON A RIVET CLINCHING MACHINE, SAIDJIG BEING USEFUL FOR POSITIONING A MULTIPLICITY OF ELEMENTS TO BECLINCHED TOGETHER BY A RIVET, SAID METHOD COMPRISING DIE CUTTING A FIRSTONE OF SAID ELEMENTS FROM A MEMBER WHEREBY SAID MEMBER IS FORMED AS ABLANK HAVING A CUTOUT SHAPED TO CONFORM WITH THE OUTLINE OF SAID ONEELEMENT, REPLACING SAID ONE ELEMENT IN SAID CUTOUT, LOCATING THEPOSITION OF SAID MEBER BY SAID ONE ELEMENT LOCATED IN SAID CUTOUTTHROUGH WHICH SAID RIVET IS TO EXTEND, AND FURTHER SHAPING SAID CUTOUTWHEREBY SAID OTHER ELEMENTS MAY BE PROJECTED THROUGH SAID CUTOUT.